Block --- 块语法

#import <Foundation/Foundation.h>
#import "Person.h"
//1.输出I love ios
void output() {
    printf("I love ios\n");
}
//2.求两个数的最大
 int maxValue(int x, int y) {
     return x > y ? x : y;
}
int main(int argc, const char * argv[]) {
    @autoreleasepool {
      
//方法一:直接打印
        output();
        
        int max = maxValue(2, 5);
        printf("max = %d", max);
   
        
//方法二:定义指针变量
        void (*p)() = NULL;
        p  = output; //指针指向对应的函数;
        p();

        int (*p)(int, int) = NULL;
        p = maxValue;
        int max =  p(2, 5);
        printf("max = %d", max);
        
        
//方法三:函数重命名(打印多个同类型,会比较方便)
        typedef int (*PFUN)(int, int);  //将函数类型重命名为PFUN
        PFUN p1 = NULL;
        p1 = maxValue;
        int max = p1(2, 5);
        printf("max = %d", max);

 //第四种方法 --- block      
 int (^max)(int, int) = ^int(int a, int b) {
            return a > b ? a : b;
        };
        //如何调用block块
       int value = max(4, 6);
        printf("value = %d", value);